src/logname.c

   1 /* logname -- print user's login name
   2    Copyright (C) 1990-1997, 1999-2002 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software Foundation,
  16    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  17
  18 #include <config.h>
  19 #include <stdio.h>
  20 #include <sys/types.h>
  21 #include <getopt.h>
  22
  23 #include "system.h"
  24 #include "closeout.h"
  25 #include "long-options.h"
  26
  27 /* The official name of this program (e.g., no `g' prefix).  */
  28 #define PROGRAM_NAME "logname"
  29
  30 #define AUTHORS "FIXME: unknown"
  31
  32 /* The name this program was run with. */
  33 char *program_name;
  34
  35 static struct option const long_options[] =
  36 {
  37   {0, 0, 0, 0}
  38 };
  39
  40 void
  41 usage (int status)
  42 {
  43   if (status != 0)
  44     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  45              program_name);
  46   else
  47     {
  48       printf (_("Usage: %s [OPTION]\n"), program_name);
  49       fputs (_("\
  50 Print the name of the current user.\n\
  51 \n\
  52 "), stdout);
  53       fputs (HELP_OPTION_DESCRIPTION, stdout);
  54       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  55       printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
  56     }
  57   exit (status);
  58 }
  59
  60 int
  61 main (int argc, char **argv)
  62 {
  63   register char *cp;
  64   int c;
  65
  66   program_name = argv[0];
  67   setlocale (LC_ALL, "");
  68   bindtextdomain (PACKAGE, LOCALEDIR);
  69   textdomain (PACKAGE);
  70
  71   atexit (close_stdout);
  72
  73   parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
  74                       AUTHORS, usage);
  75
  76   while ((c = getopt_long (argc, argv, "", long_options, NULL)) != -1)
  77     {
  78       switch (c)
  79         {
  80         case 0:
  81           break;
  82
  83         default:
  84           usage (EXIT_FAILURE);
  85         }
  86     }
  87
  88   if (argc - optind != 0)
  89     usage (EXIT_FAILURE);
  90
  91   /* POSIX requires using getlogin (or equivalent code).  */
  92   cp = getlogin ();
  93   if (cp)
  94     {
  95       puts (cp);
  96       exit (EXIT_SUCCESS);
  97     }
  98   /* POSIX prohibits using a fallback technique.  */
  99   fprintf (stderr, _("%s: no login name\n"), argv[0]);
 100   exit (EXIT_FAILURE);
 101 }